# Exceptions - `HTTPException` and `WebSocketException`

These are the exceptions that you can raise to show errors to the client.

When you raise an exception, as would happen with normal Python, the rest of the execution is aborted. This way you can raise these exceptions from anywhere in the code to abort a request and show the error to the client.

You can use:

* `HTTPException`
* `WebSocketException`

from starlette import status as status

from .applications import FastAPI as FastAPI
from .background import BackgroundTasks as BackgroundTasks
from .datastructures import UploadFile as UploadFile
from .exceptions import HTTPException as HTTPException
from .exceptions import WebSocketException as WebSocketException
from .param_functions import Body as Body
from .param_functions import Cookie as Cookie
from .param_functions import Depends as Depends

                    }
                } catch (ModelParserException e) {
                    exceptions.add(e);
                }
            }
            try {
                return doRead(request);
            } catch (IOException e) {
                exceptions.forEach(e::addSuppressed);
                throw e;
            }
        } else {
            return doRead(request);

  @JvmStatic
  val windows: Boolean
    get() = System.getProperty("os.name", "?").startsWith("Windows")

  /**
   * Make assertions about the suppressed exceptions on this. Prefer this over making direct calls
   * so tests pass on GraalVM, where suppressed exceptions are silently discarded.
   *
   * https://github.com/oracle/graal/issues/3008
   */
  @JvmStatic

import org.jetbrains.kotlin.fir.symbols.resolvedCompilerRequiredAnnotations
import org.jetbrains.kotlin.fir.utils.exceptions.withFirEntry
import org.jetbrains.kotlin.name.*
import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
import org.jetbrains.kotlin.utils.exceptions.checkWithAttachment
import java.lang.annotation.ElementType

   * RuntimeException runtime exceptions} thrown by the executor.
   */
  @SuppressWarnings("CatchingUnchecked") // sneaky checked exception
  private static void executeListener(Runnable runnable, Executor executor) {
    try {
      executor.execute(runnable);
    } catch (Exception e) { // sneaky checked exception

import org.jetbrains.kotlin.psi.KtStatementExpression
import org.jetbrains.kotlin.psi.psiUtil.getQualifiedExpressionForReceiver
import org.jetbrains.kotlin.utils.exceptions.errorWithAttachment
import org.jetbrains.kotlin.utils.exceptions.withPsiEntry

internal class KtFirCompletionCandidateChecker(
    override val analysisSession: KtFirAnalysisSession,
    override val token: KtLifetimeToken,

import org.jetbrains.kotlin.resolve.calls.util.getCalleeExpressionIfAny
import org.jetbrains.kotlin.util.OperatorNameConventions
import org.jetbrains.kotlin.utils.exceptions.errorWithAttachment
import org.jetbrains.kotlin.utils.exceptions.withPsiEntry

internal class KtFirImportOptimizer(
    private val analysisSession: KtFirAnalysisSession,
    override val token: KtLifetimeToken,

import org.jetbrains.kotlin.name.FqName
import org.jetbrains.kotlin.name.Name
import org.jetbrains.kotlin.psi.KtElement
import org.jetbrains.kotlin.psi.KtFile
import org.jetbrains.kotlin.utils.exceptions.errorWithAttachment
import org.jetbrains.kotlin.utils.exceptions.withPsiEntry

internal class KtFirScopeProvider(
    override val analysisSession: KtFirAnalysisSession,
    private val builder: KtSymbolByFirBuilder,

import org.jetbrains.kotlin.psi.KtOperationReferenceExpression
import org.jetbrains.kotlin.psi.psiUtil.parentsWithSelf
import org.jetbrains.kotlin.utils.exceptions.errorWithAttachment
import org.jetbrains.kotlin.utils.exceptions.withPsiEntry
import java.util.Optional
import kotlin.collections.ArrayList
import kotlin.jvm.optionals.getOrNull
import kotlin.math.sign

@OptIn(KtAnalysisNonPublicApi::class)